U.S. Pat. No. 8,747,367 discloses an injection device in which, in order to set an injection dose, a dosing member is rotated until the desired dose appears in a window. On account of the rotation, the dosing member moves in the distal direction of the injection device, that is, moves away from an injection needle placed on the injection device. The injection device has a latching device which has a multiplicity of latching positions. As a result, the user can also set the dose by counting a number of palpable or audible latching positions. It is not possible to set intermediate positions between two latching positions. The injection device can have a torsion spring which is without function when setting a dose. When ejecting a set dose from the container, the torsion spring supports the rotation of the setting member and thus the injection.
With the injection device shown in U.S. Pat. No. 8,747,367, a wide variety of quantities of injection fluid can be set. The possible quantities to be set are defined by the latching device. The operating element jumps into the nearest intended position from positions of the operating element which correspond to quantities of injection fluid that are not intended by the manufacturer.
In order that the operating button jumps automatically and reliably from an intermediate position into a latching position, the catch has to be sufficiently strong and the radial latching positions must be located close enough together. However, the strength of latching influences the torque which the user has to apply in order to rotate the operating button and set the dose. The structurally possible spacing of the latching positions is largely defined thereby and can be adapted to the application case only within narrow bounds.